


See Sea Cecaelia

by CasualOtaku



Category: Batman (Comics), Batman - All Media Types, Red Hood and the Outlaws (Comics), Red Robin (Comics), Under the Red Hood
Genre: Cecaelias, Fluff and Crack, Jason Todd Has Tentacles, Jaytim - Freeform, M/M, MerMay, Mermen, Pseudoscience, Tentacles, Transformation, Tumblr: Tentatodd Week, no beta we die like men, tentatodd
Language: English
Status: In-Progress
Published: 2020-06-01
Updated: 2020-07-18
Packaged: 2021-03-02 22:47:48
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 4
Words: 3,276
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24484564
Author URL: https://archiveofourown.org/users/CasualOtaku/pseuds/CasualOtaku
Summary: “My son is a cephalopod, Arthur!  This isn’t a laughing matter.”
Relationships: Tim Drake & Jason Todd, Tim Drake/Jason Todd
Comments: 26
Kudos: 211





	1. Chapter 1

**Author's Note:**

> I wanted to get SOMETHING done for Mermay. I'm a day late and at least a chapter short, but it's...something?

Red Robin blinked and nearly screamed as his vision cleared and his lap was suddenly filled with a mass of writhing tentacles and half a human torso. Then the tentacles shifted some more and he realized it wasn’t just a torso but an entire upper body attached to said tentacles.

The teen goggled then let out a choking sound as a few of those tentacles slapped against his lips and CLUNG.

He instinctively began trying to peel them away only to have others try to cling to other parts of his body. “Damnit Jason! Cut it out!”

Rather than answer the pseudo-eldritch horror in his lap sniffled before letting out an angry hiss.

Red Robin winced as he got a good look at Jason’s face realized that not only was he dealing with a transformed Jason Todd, but a deaged Jason Todd as well. All while the man behind it made a quick getaway.

“Damnit. How the hell am I going to explain this one?” Red Robin lamented as he got to his feet with Jason still clinging to his chest.

\---

Red Robin was still dreading the upcoming conversation when he entered the Batcave with Jason still firmly attached to his chest and occasionally poking at his domino.

Batman looked up from his reports and stared in open shock at Red Robin and his new chest piece. “Red Robin? Hood? What happened?!”

“Madman with a ray gun.” Red Robin answered. “Jason jumped into the line of fire and well...this.”

Batman headed over and looked at the pair a moment before reaching out to help remove Jason from Tim’s chest. He pulled as hard as he dared but only succeeded in stretching the tentacles out before Jason literally slapped him across the face and let out a hiss. Batman quickly let go and Jason went right back to his literal octopus hug.

“Damn. I guess he really is, err...attached.” Red Robin said before he peeled back his cowl. “I was hoping it was just him trying to hitch a ride back here for help. Maybe he’ll let go if we can get him in some water?”

“...I’ll go fill the tank.” Batman said. “Then we can review the footage for more details and call in some help.” 

Red Robin nodded, ever thankful Batman had enough crazy contingency plans to warrant having a large water tank that could hold someone like Killer Croc. He began to remove his costume, hoping that maybe Jason would come off with it, but Jason just shifted about to attach to the newly bared skin instead. It was the strangest sensation ever, not painful per se, but decidedly uncomfortable.

Eventually Tim got down to his boxer briefs and sighed as Jason slid his way around to his back and began nibbling on the younger man’s shoulder. Again, it wasn’t painful per se, but it was a bit uncomfortable considering Jason was his boyfriend but looked like a kid and very tentacley at the moment.

“The tank is ready for you.” Batman said. “I made the salinity equal to ocean water just in case.”

Tim nodded and headed for the tank before climbing inside. Jason relaxed slightly once they were both submerged, but didn’t fully release his hold on his boyfriend, choosing to keep one tentacle wrapped firmly around Tim’s torso as he explored the tank with his other appendages.

Tim sighed and settled in for what would not doubt be a couple hours of soaking while Batman tried to find a way to reverse the change. Hopefully nature wouldn’t call before then because he really didn’t relish the idea of suction cups trying to attach to any bared skin down there.

Across the floor, at the Batcomputer, Batman poured over the video feed from Red’s visor, going frame by frame until he saw something familiar. He quickly opened a communication channel with the Watchtower and asked them to get in touch with Aquaman. After that it was a long wait as he continued to meticulously go over the footage until Aquaman finally returned his call.

“Batman. Strange to hear from you of all people.” Aquaman said. “What’s gone wrong?”

“I’m sending you a screenshot now.” Batman said. “Red Robin and Red Hood ran afoul of someone carrying a weapon with that inscription. It’s Atlantean, correct?”

“...wow. I thought we’d gotten rid of all those things.” Aquaman said after a moment.

“All of what things?” Batman demanded. “What kind of weapon is it?”

Aquaman laughed a bit. “It’s not a weapon.”

“My son is a cephalopod, Arthur! This isn’t a laughing matter.”

Aquaman blinked, then laughed even more. “Oh wow. Most people get fish tails. Your son must be an Ursula fan or something.”

Batman felt one eye twitch slightly as he forced himself to stay calm. “Arthur.”

“Calm down. They were a failed experiment in giving humans the ability to survive in water like an Atlantean.” Aquaman said. “Failed being the operative word. They just ended up turning into kid mermen for a week or so.”

“So he’ll go back to normal?” Batman asked.

“Yep. Just keep him moist and well fed and he’ll be none the worse for wear.” Aquaman replied.

“Thank goodness.” Batman murmured. “But why kids?”

“More plasticity.” Arthur replied. “Think how quickly kids tend to bounce back from injuries. They thought they could keep the mind intact, but they just ended up with kid minds merged with animal instinct. They could never find a fix so the project was abandoned. I realized the potential for it to be weaponized though so I had all but one of them destroyed. Which means I have some sleuthing of my own to do. Later!”

Batman opened his mouth to ask something else but Aquaman was already gone. Bruce rubbed at his temples. It wasn’t the worst news he could have been given, but it also wasn’t the best. And he still had no clue how to get Jason off Tim without literally tearing him away. And even if he knew octopi could regrow limbs he had no desire to accidentally tear off a piece of his son’s body. Who knew if that regeneration carried over to a hybrid?

He’d just have to figure it out as he went and wait for Jason to change back without going crazy with worry. Somehow.


	2. Chapter 2

**Summary for the Chapter:**

> Dick gets tagged in.

Tim sighed as Jason dunked a tentacle into his cold brew and swished it about. He supposed that was an upgrade from flat out swatting it out of his hands like the two cups of hot coffee he’d tried before, but it was the principle of the thing. He was too tired to even try to remove the tentacle this time so he just steeled himself and drank from the cup with the appendage still present. He got a subtle hint of salt from the moisture on Jason’s skin, but it wasn’t THAT bad and he wanted caffeine more than he wanted unadulterated flavor.   
  
He’d barely slept a wink last night and he needed the jolt to keep him going through his online classes. Honestly it served him right for leaving his coursework to the last minute but he’d been so caught up between his duties at WE and as Red Robin that he simply hadn’t had time to get ahead. And honestly on a normal day he would have been able to breeze through the assignment with ease.

Having a tentacle baby attached to his back and randomly poking at everything around him made it far from a normal day, even by Bat standards.   
  
Tim finished off the coffee and set aside the empty cup just as the elevator doors opened and he heard the light rattle of a cart. He couldn’t help but smile a bit as Alfred approached the workstation bearing a second cup of coffee and a beautiful tray of fresh sushi and sashimi.   
  
Jason immediately slithered off Tim’s back to attack the tray, but kept one tentacle around Tim as always. Alfred whipped out a spray bottle as Jason ate and gently misted the cecaelia down as he spoke. Honestly it was almost magical how the old butler remained as unflappable as ever.   
  
“Ah, it seems I shall have to fetch another tray. I did not anticipate him having quite that large an appetite.”    
  
Tim shrugged and gratefully took a deep swallow of the pure coffee, savoring the chance to enjoy something that hadn’t been fondled by his transformed boyfriend. “I’m just glad he’s occupied for the moment. Did Bruce have any luck getting in touch with Zatanna about expediting the process?”   
  
“Indeed.” Alfred replied. “She will be arriving later this evening. In the interim we’ll have to ask you to continue to keep yourself in or near the water at regular intervals.”   
  
Tim nodded. He didn’t need the reminder after he’d tried to sleep in his own bed with a humidifier going to keep Jason moist. They’d made it to four hours before he was awoken by Jason thrashing around and literally dragging him to the bathroom to try and squeeze into the toilet for moisture. Luckily Tim had realized what was going on and was able to slam on the shower and get Jason to go in there instead. After that he’d just gone back to the tank and only stepped out for a couple hours at a time to work on assignments and see to his bodily functions.   
  
Bruce didn’t want to risk long term damage to Tim’s skin through constant submergence, especially considering his missing spleen. So cycling between his needs and Jason’s seemed like the best compromise until Zatanna arrived since Aquaman had gone dark after realizing someone had gotten into his armory.   
  
Jason finished all but one piece of unagi which he shoved at Tim’s lips, smearing the sticky eel sauce about until Tim obligingly opened his mouth and allowed himself to be fed. It would have been almost sweet if it didn’t mean a few tiny suction cups stuck to his lips until Jason pulled them away.   
  
“Okay, I’m not sure if that’s adorable or utterly creepy.” Dick said as he wandered closer to the tank.   
  
“Ah. Master Dick, I had not realized you had arrived.” Alfred said. “I take it you came to check on Master Jason?”   
  
Dick nodded and headed over to peer at Jason, who stared right back before slapping a pair of tentacles against Dick’s cheeks and pulled. Dick grimaced as his skin was stretched outward, then pushed back in, over and over.

  
“Okay, okay...you can let go now, Little Wing.” Dick gasped.   
  
Rather than let go, Jason crawled onto Dick’s chest before wrapping him up in a literal octopus hug.

Tim just smiled and lifted his phone to take a picture. “Tag. You’re it. I’m going to go finish this upstairs and lay down in an actual bed.”   
  
“Wait! Tim! I don’t know what to do yet!” Dick called out.   
  
“Grab some trunks and get ready for your time in the tank.” Tim called out as he headed for the elevator “Have fun!”


	3. Chapter 3

**Summary for the Chapter:**

> Zatanna arrives and has about as much luck as she usually does in this trope.

Dick sighed as he floated on his back in the pool while Jason swam laps, happily dragging the older man along with him like a floatie. They could only stay in the water so long because of the chlorine level, but Jason seemed to appreciate having the room to jet about and stretch his le--err tentacles. Of course that came with Dick having to awkwardly flail about until they’d figured out it was best for Dick to just lie limp and let Jason do all the work.  
  
It. Was. So. Boring.   
  
He couldn’t begrudge Tim the chance to sleep though. His little brother got so little rest that Dick wasn’t about to disturb it just because Jason had decided he would make a good perch. So until Tim woke up it seemed he was the babysitter, of sorts.   
  
“Well now, this is one for the scrapbook.”

Dick blinked and tried to shift upright only to end up going under and sinking like a stone as Jason shifted his grip.   
  
“Esir evoba eht retaw.’ Zatanna called, taking both Dick and his rider in a mystical grip before lifting them above the water. She let them drip off for a bit before lifting her phone. “Smile little birdies!”   
  
Jason happily waved his tentacles about and grinned obligingly while Dick just looked a bit desperate.   
  
“Please, please say there’s something you can do.” Dick said. “I love him and all but I haven’t had full use of my arms since he latched on. I couldn’t even eat a bowl of cereal. He just kept yoinking the box out of my hands while shoving apples and wheatgrass at my mouth.”   
  
Zatanna laughed and gently set Dick back on his feet at the side of the pool. “Sounds like Jason is definitely still in there.”   
  
“Zaaaaat.” Dick whined.   
  
“Come on, Dick. Chin up. You’re supposed to be a big boy.” Zatanna replied before she padded over. “Bruce says he’s been hissing when people try to remove him.”   
  
“Mainly when HE tries to remove him, but yeah.” Dick said as Jason began poking at Zatanna’s hat.   
  
That magician chuckled and removed said hat before waving her hand above the surface. A tarot deck rose from within and began shuffling itself midair before expanding outward to spin all around them.   
  
“Laevr eht eruc rof Nosaj’s noitidnoc ot em.’   
  
Three cards separated themselves from the rest and flew over to float before her eyes as the others dove back into the hat and vanished from view.   
  
“Well I have good news and bad news.” she said.   
  
“Bad news first.” Dick said before she could ask.   
  
“There’s nothing I can do. You’ll just have to wait it out.” she said before waving her hand and sending the three cards into her hat as well.   
  
“And the good news?” Dick asked.   
  
“It really is just temporary.” she said as she set the hat back on her head with a flourish, only to laugh as Jason slapped his little hands and tentacles together in a semblance of applause. “Aww. You’re just the cutest wittle tentacle beastie. Aren’t you?”   
  
Jason let out a happy little burble as Zatanna ruffled his hair.   
  
“Think you could be a good boy and let poor Dickie go?” she asked.   
  
Jason’s face immediately fell before he wrapped himself around Dick’s head and neck, only leaving his eyes and nose peeking out.   
  
Dick let out a muffled cry of distress as Zatanna did her best not to laugh.   
  
“Grayson! Have you still not extricated Todd from your person?” Damian asked as he burst into the room and marched up to Dick’s side. “Pennyworth has requested your presence in th--”   
  
Jason suddenly whipped out a tentacle and wrapped it around Damian’s head and mouth earning several furious, yet muffled screams as he slithered his way over to his younger brother’s shoulder.   
  
Dick let out a sigh of relief as he was finally able to breath properly again. “You okay there, Dami?”   
  
Damian let out another muffled tirade and struggled in Jason’s grip.   
  
“Gonna take that as a yes.” Dick said as he grabbed hold of Zatanna’s hand. “So, I’m gonna take Zat upstairs for tea and grab something to eat while you bond with Baby Jay. Later!”   
  
Damian’s eyes widened as he tried to voice his opposition to this plan before he began struggling anew. All to no avail. Clearly his brothers hadn’t been exaggerating when they said Jason’s grip could rival that of a Kryptonian. Damian was left with no choice but to simply glare his displeasure as Grayson fled _/Coward!!/_ with the magic user and Jason lifted him overhead for ease of transport back to the tank.   
  
He didn’t know how; he didn’t know when; but Damian vowed that he would have vengeance for this affront once Todd regained his human form. Surely he could recruit his other brothers to his cause. After all Jason’s immature behavior was clearly costing them all both sleep and sanity. Surely there had to be some method of getting the troublesome oaf to remain in his tank alone. He had better things to do than act as a distraction to an octopus monster, even if said monster was technically his brother. Father didn’t have to endure this after all.


	4. Chapter 4

**Summary for the Chapter:**

> Damian's brothers are less than helpful.

**Notes for the Chapter:**

> Sorry this chapter is so short, but Damian was being unhelpful and just sitting there glaring at me. So I wrote a chapter where that's all he did.

“Wow. That is one very intense glare of doom Dami has going.” Tim said as they watched their youngest brother floating in Jason’s tank. 

Damian’s eyes narrowed as he heard the assessment and a few bubbles escaped the edges of his snorkel as he let out a small ”-tt-”.  
  
“I’m just impressed he’s held that position for so long without trying to break free and find stabbing implements.” Dick said. 

“Think we should wake Jason up from his nap?” Tim asked. “I’ve been dry for a few hours now so I can take over again.”  
  
“Might be a good idea. “ Dick answered. “I don’t want Dami trying to turn Jason into calamari.”  
  
“Isn’t calamari squid?” Tim asked  
  
“Yeah, but it rolls off my tongue better than polvo guisado.” Dick replied.  
  
“Damn...octopus stew does sound good though.” Tim mused, rubbing his chin.  
  
“Tim!” Dick gasped.  
  
“What? It’s not my fault octopus is delicious.” Tim insisted. “I’m not saying I’d actually eat any, not until after Jason is back to normal anyway.”  
  
“I don’t know if I’ll ever be able to eat it again.” Dick said. “He kept slapping his tentacles onto my mouth to steal food and pull my cheeks.”

“Hey, it’s not like he wasn’t doing the same to me.” Tim said. “Not to mention he wouldn’t let me go past four cups of coffee and two of those had to be cold brew.”  
  
“You were supposed to be cutting back on your caffeine.” Dick said. “I’m pretty sure he was just trying to make sure you did that. He was denying me cereal, Tim. Cereal!”  
  
“Try something unsweetened.” Tim shot back with a dry look.  
  
“Blasphemy!” Dick hissed. “Breakfast cereal isn’t breakfast cereal if it isn’t sweet.”  
  
“You know that stuff has almost no nutritional value, Dick. Try eating a vegetable omelette or something.” Tim suggested. “It’s clear Jay is just trying to keep us healthy in his own annoying way. He hasn’t been slapping food or drinks out of Damian’s hands after all. Right?”  
  
“He hasn’t let him eat or drink, period.” Dick said. “According to the cave’s footage Jason just shoved the snorkel into Damian’s hands and dragged him under instead of letting him float at the surface like he did with us.”  
  
Tim hummed and rubbed at his chin. “I wonder why he dragged him under? Maybe the fact Damian’s shorter means Jay had to stretch his tentacles out more? It bears thinking about. Also, I want copies of that footage.”  
  
“Done.” Dick said as he pulled out his phone and sent a copy of his copy to Tim’s inbox. “And personally I think it was the easiest way to ensure Dami couldn’t spend the entire time snarling at him. It’s a lot harder to swear when you’re biting down on a snorkel.”  
  
Damian felt his eye twitch as his brothers continued to banter back and forth, utterly making light of his plight. Clearly he was going to have to reassess his initial plan to have them assist in his future retribution against Todd. Instead they would need to be included in the path of his ire. And they would all feel his wrath. All Todd was doing by keeping him entrapped was giving him time to plan. And his vengeance would be glorious.

**Author's Note:**

> Cecaelia are merpeople too!


End file.
